Floor polisher



D. so, 1941. F E, BROBERG 2,268,015

FLOOR POLISHER l Filed Jan. 3, 1941 2 Sheets-Sheet l i. Z l INVENTORATTO RN Ejr.

F. E. BRoBl-:RG

FLOOR POLISHER Filed Jan. 5, 1941 2 sheets-sheet 2 INVENTOR ATTORNEY.

Patented Dec. 30, 1941 2,268,015 FLOOR POLISHER Fred E. Broberg, Racine,Wis., assigner, by mesne assignments, to S. C. Johnson & Son, Inc.,Racine, Wis., a corporation of Wisconsin Application January 3, 1941,Serial No. 373,019

13 Claims.

tively light weight, while economical of manufacture, have not thus farbeen entirely satisfactory.

It is therefore a primary object of my invention to provide an improvedlight weight polisher of the type employing a brush which rotates abouta vertical axis and wherein the brush provides the sole support for themotor and its mounting structure, whereby higher brush speeds than haveheretofore been thought practical may be safely employed with aresultant increase in the Work capacity of the device.

A further object of the invention resides in the provision of improvedmeans for the manual control of a high speed polisher of the disk brushtype.

More specifically it is an object of this invention to provide apolisher of the single disk type with an improved handle which permitsstabilization of the polishing brush during its high speed rotation incontact with surfaces which set up unbalanced torsional stresses withinthe brush.

A still further object is to provide a handle controlled polisher of theabove type with resilient means within the handle to allow relativemovement between portions thereof for the absorption of torsionalstresses and vibrations which, if unabsorbed, tend to amplify to theextent that the polisher becomes uncontrollable.

And still another object of the invention is to provide a polisher ofthis type with improved means for pivoting the handle to the polisherframe in a manner whereby said pivotal mounting cooperates withresilient means within the handle to provide stabilization and improvedcontrol of the device during use.

A further object is generally to simplify and improve the construction,arrangement and operation of polishers for one or more of the purposesmentioned, and still other objects will be apparent from thespecication.

The invention includes the construction and arrangement of parts asherein illustrated, described and claimed and. since variousmodifications thereof are contemplated, it will be understood that theinvention also includes such modifications as are equivalent to theclaims.

The same reference characters have been used for the designation of likeparts throughout, and in the drawings:

Fig. 1 is a top plan view of a floor polisher.

Fig. 2 is a side elevation of the device shown in Fig. 1.

Fig. 3 is an enlarged sectional view on the line 3-3 of Fig. 1.

Fig. 4 is an enlarged sectional view on the line 4-4 of Fig. 1.

Fig. 5 is a sectional view on the line 5-5 of Fig. 4; and

Fig. 6 is a perspective view of the mounting bracket shown partially cutaway in Fig. 4.

As shown in Figures 1 and 2, the device includes a downwardly openinghousing or frame I0, a motori II mounted thereon, a disk type rotarybrush I2 provided with a rigid brush block I3 and disposed withinhousing I0, and a shaft I4 carried by block I3, said shaft beingsuitably journaled for rotation with respect to frame I0 and connectedto motor I I through drive mechanisms I8 and Il and reduction units I8and I9.

A handle, generically designated by reference numeral 23 includes arigid forked portion 24 having its fork arms pivoted to frame I0 onopposite sides of motor I I as hereinafter described, an elongated rigidportion 25 adapted to be gripped by an operator and a universallyyieldable connector 21 between fork 24 and handle portion 25.

As shown in Fig. l, housing I0 is provided with a pair of slots oropenings ,28 disposed on opposite sides of the motor to allow extensiontherethrough of the lower fork arm portions.

As best shown in Figures fl and 5, the end of each fork arm is providedwith oir-set portion 30 which carries an insert |30 of hardenedmaterial, said insert being provided with a transverse bore throughwhich apintle bolt 3l carried by frame I0 projects to permit pivotalmovement of the fork arm through a vertical plane with respect to frameI0. Bolt 3I is carried intermediate a pair of brackets 33 and 34 whichare welded to the bottom wall of, housing I0 to depend therefrom. Bolt3I is provided witha hexagonal head and the depending arm of bracket 33is provided with a complementary aperture, as best shown in Fig. 6, toreceive the bolt head in axially slidable but nonrotatable relationthereto.

A dish-like resilient washer 35 is disposed intermediate the bolt headand the adjacent surface of insert |30 to provide frictional thrustengagement between the fork arm and bracket 34 when clamping pressure isapplied to the bolt as hereinafter described. Bolt 3| includes acylindrical bearing portion 31 on which the fork arm pivots and areduced portion 38 having a nut 38 in threaded engagement therewith. Awasher 40 5 is disposed between bracket 3l and the adjacent side ofinsert |30. Bearing portion 31 of bolt 3| projects through washer 40whereby annular shoulder M between bearing portion 31 and reducedportion 38 of bolt 3| abuts bracket 34 to l0 ther tightening of nut 39does not increase the 20 thrust which washer -35 exerts on the fork armto provide the desired yieldable frictional engagement between the armand bracket 3l. It

' is therefore possible to rapidly assemble the structure without trialand error adjustments to v2:5

obtain the exact amount of thrust desired.

Universal connector 21 includes a housing 5l,

threadedly engaging an annular shoulder 5| which may be an integralextension of fork arm 24. Shoulder 5| projects upwardly from a flat- 30tened upper portion of the fork 2l in a position midway between the forkarms. Housing l is provided with an interior chamber including acylindrical passageway 53 leading from the outer end thereof into anenlarged cylindrical pas- 35 sageway I which in turn leads into afurther enlarged cylindrical portion 55. Elongated handle portion has acylindrical end section projecting through chamber portions 53 and 5land into portion 55 to terminate at a point spaced 0 from the ends ofsaid chamber portion. A sleeve 58 is carried by that section of thehandle disposed within chamber 4portions 54 and 55. Sleeve 58 ispreferably in press fit engagement with handle 25 and may be weldedthereto to 45 prevent relative movement between the sleeve and handle. Aflange 53 extends radially from sleeve 58 at the handle terminus, saidange being an integral portion of the sleeve. The outer wall of ange59is in spaced relation tothe in- 50 ner side wall of chamber portion55, and the periphery of sleeve 58 and handle 25 are in spaced,

relation to the inner walls of chamber portions 54 and 53 respectively,whereby to allow relative movement between the handle and sleeve assem-55 bly and the housing v5|I.

An annular resilient bumper 80, rectangular in cross section, isdisposed between the bottom wall of chamber portion 55and the bottomsurface 'of flange 59, and an annular resilient 60 bumper 62 which maybe circular in cross section is disposed between the top wall of chamberportion 55 and the top wall of ilange 53. A pin 6| is anchored in theflat portion of fork 2| to project through suitable bores in bumper 50and 65 flange 59 respectively, whereby to constrain the bumper andflange against rotation relative -to the fork and housing 50.

The mounting of handle portion 25 between and the provision of spacebetween the chamber walls and adjacent portions of the handle and itsattached sleeve 58 permits limited movement in all directions betweenthe rigid handle portion resilient bumpers within the chambered housingsubstantially dampened within the connector to' arrest their effectivetransmission to the brush. I have found that the device works well whenthe distribution of weight of the brush and the structure directlysupported thereon is such that the horizontal axis about which the forkyarm f pivots is preferably' somewhat below the center A housing 18 isremovably attached to frame I0 to protect the motor from dust and injuryand to add an attractive appearance to the device. A pair of shroud-likeguards 1| are mounted to frame I 0 to project marginally from fork armopening 28, whereby to provide bumper means forl limiting the pivotalmovement of the forkv arm. A protective bumper 13, which may be ofrubber, encircles the lower margin of frame I8 to'provide cushioningmeans during contact of the divice in operation with objects such asfurniture.

'I'he arms of fork 24 are provided with a passageway 15 which extendsfrom the fiat top portion of the fork to points below the top wall offrame housing I0. A bore 18 leads through shoulder 5| and intopassageway 15. A detachable connector plug 11 is partially disposedwithin the lower end of tubular handle 25 and par# tially disposedwithin bore 18 and passageway 15, whereby to provide convenientdisassembly of the .electrical connections upon removal of housing 58.Bore 16 is of suillcient size to allow substantial space between thewalls thereof and the periphery of plug 11, whereby the plug will notbind in respect to oil'set portion 5| during flexing of connector 21.Plug 11 is preferably pinned at 18 to handle member 25 and sleeve 58.

Electrical leads extend through handle 25 and are electrically connectedto plug 11 to be divided and separately extended through the fork armsto points below the frame where they are connected by suitable means tomotor Il.

Uneven pressures at various parts of the disk brush with respect to thesurface to be polished are encountered in the ordinary operation of thepolisher by virtue of an uneven floor or as the result of the polishercoming into contact with objects such as furniture or showcases. Thetorque reaction at the point of increased brush pressure tends to liftthe entire polisher at this side and to depress the opposite side of thepolisher whereby a corresponding condition of increased unbalanced brushpressure is produced. The action therefore repeats itself with rhythmicregularity and with increasing amplitude until the polisher capsizes.

The above described improvements co-act to prevent an increase inamplitude of said rhythmic vibrations by allowing the brush and the'tions as a shock absorber while the yielding re- 25 and the rigid fork.whereby vibrations and 7 sistance applied to the pivotal connection ofthe handle fork arms prevents the rhythmic vibra.- tion of the polisherabout its horizontal axis. 'The eiect of the cooperation of theyieldingly resistant universal joint with the restricted movement of thepolisher about the fork mounting axis provides a polisher of highefiiciency which operates smoothly and which can readily be moved aboutby the operator. The entire construction is compact and of distinctlyimproved appearance.

Having thus described the invention, I claim:

l. In a device of the character described, the combination of a frame, apolishing member journaled thereto to rotate about a substantiallyvertical axis and mounted beneath said frame, a motor mounted on saidframe, drive means intermediate the motor and polishing member, and ahandle pivotally connected to the frame, said handle comprising apivoted fork portion, an elongated rigid portion, and resilientuniversal joint means intermediate the iork and 4elongated handleportions.

2. In a device of the character described, the combination of a frame,Aa polishing member journaled thereto to rotate about a substantiallyvertical axis and mounted beneath said frame, a motor mounted on saidframe, drive means intermediate the motor and polishing member, and ahandle connected to the frame, said handle comprising a fork portionpivotally engaging said frame in clamping relation lthereto, anelongated' rigid portion, and resilient universal joint meansintermediate the fork and elongated handle portions.

3. In a device of thecharacter described, the combination of a frame, apolishing member journaled thereto to rotate about a substantiallyvertical axis and mounted beneath said frame, a motor mounted on saidframe, drive means intermediate the motor and polishing member, and ahandle comprising a rigid portion connected to the frame, a second rigidportion extending from said first mentioned portion, and resilientuniversal joint means intermediate the handle portions.

4. In a device of the character described, a

posite sides of the motor along an axis at right angles to the axis ofbrush rotation, and clamp means intermediate the frame and fork handlesection whereby to yieldingly resist pivotal movement of the handle withrespect to the frame.

7. A deviceas described in claim 6 wherein the clamp means includes apair of bracket arms mounted to the frame, a plntle bolt supported bysaid arms and pivotally engaging the forked handle section, a springwasher carried by the bolt,' and clamp means carried by the bolt forpressure engagement of the handle section and one of the bracket armsunder distortional pressure of the washer, said bolt being provided witha shoulder for engagement with said bracket arm upon a predetermineddistortion of said washer whereby to limit the pressure engagement beinwhich the entire weight of the polisher rests upon the brush, a frame,a. polishing member mounted for horizontal rotation beneath the frame, amotor mounted upon said frame in operative connection with said member,and a handle including a fork and an elongated member, said fork beingpivoted to the frame along a horizontal axis extending below the centerof mass of the frame, brush and motor, and said elongated member beingresiliently mounted on said fork at a point substantially midway betweensaid fork arms, and means to yieldingly resist the pivotal movement ofthe fork arms .with respect to the frame.

9. A floor polisher including a brush ,iournaled handle adapted tostabilize torsional stresses initiated in the device during operationand comprising a rigid fork provided with a chamber positionedsubstantially midway Abetween the fork arms, a rigid elongated memberhaving one end loosely disposed within said chamber for relativemovement between the fork and elongated member, and means disposedwithin the chamber for the retention of the end portion of saidelongated member therein in resilient engagement with said fork.

5. A device as set forth in claim 4 whereintype brush disposed beneaththe frame in bearing relation therewith for rotation about a verticalaxis and to provide the sole support for said motor and frame, a handlecomprising a forked section and an elongated section and a iiexibleconnection between the handle sections, said fork section pivotallyengaging the frame on opsuperposed relation thereto and supported on thebrush, an electric motor mounted on said frame,

drive means connecting the motor to the brush for the rotation thereof,a handle comprising a.`

lower forked tubular section and an upper elongated tubular section,said lower section being pivoted to the frame, and said upper sectionbeing connected therewith through a resilient universal joint, -achamber extending centrally through said universal joint and connectingsaid tubular sections to provide a passageway throughout the handle,electrical connections extending through said passageway and connectedto said motor, said connections including a detachable plug mounted insaid passageway and having a. portion attached to said upper section anda portion 'projecting into said chamber in spaced relation to the wallsthereof whereby to prevent engagement between the plug and the chamberwalls during flexing pf said universal joint.

l0. In a device of the character described, a frame, a pair oi.'brackets mounted thereto, a plntle bolt supported by said brackets, anda handle disposed between the brackets in pivotal engagement with thebolt, said bolt including a at sided head, a cylindrical bearing portionand a reduced threaded portion to provide a shoulder therebetween, oneof said brackets being pro-V vided with an aperture complementary tosaidfiat sided bolt head, said head being disposed therein in axiallyslidable and nonrotatable relation thereto, the other bracket beingprovided with a bore through which said reduced portion projects, athrust washer carried by said bolt intermediate one of the brackets andthe handle, and a nut threadedly engaging said reduced portion for thelimited clamping engagement of the handle as predetermined by theshoulder on the bolt.

11. A floor polisher comprising a frame, a poiishing member rotatablymounted on the frame, a motor carried by the frame and in operativedriving connection with the member) and a handle for said framecomprising a first section in pivotal connection with the frame and asecond section universally connected to the rst section, together withresilient means opposing relative universal movement between saidsections.

12. A floor polisher comprising the combination with a rotary polishingbrush, of a motor support having bearings for said brush and havlng itsweight carried by said brush, a motor on l5 said support in operativedriving connection with r said brush, and a guiding handle for saidpolisher comprising a plurality of universally jointed sections, one ofwhich is pivotally connected to said support, said handle having anelastic centering means mounted on one of said sections and engaging theother to resist universal movement therebetween.

13. A motor driven iloor polisher comprising the combination with arotatable polishing brush,

a motor support carried by said brush and hav-

